Recently, I got an interesting piece of hardware called the "Demo Vision". It is another one of those WideBoy-type devices that use NES hardware.
Recently, I got an interesting piece of hardware called the "Demo Vision".
It is another one of those WideBoy-type devices that use NES hardware.
The Demo Vision is an oldskool GameBoy development kit consisting of a large unit in a steel case, and 1 or 2 GameBoy units that connect to it via cables. The GameBoys are wired to draw power from the main unit, and to send their audio and video data to the main unit. Games are inserted directly into the GameBoys, and the image and sound are displayed simultaneously on the GB screen & speaker and Demo Vision's A/V outputs.
Inside the Demo Vision are up to 2 NES/Famicom motherboards, each with individual RF and composite AV outputs. Each NES has EPROMs for PRG and CHR data, and there is an on-board MMC5 mapper (to control timing/RAM??). The CHR ROM is revision A, and the PRG ROM is revision B.
Of course, the two parallel Game Boy units were meant for link-up playtesting. So, I put in Tetris and hooked up each of the Demo Vision's video outputs. When both GB's power switches are turned on, both GBs boot simultaneously.
And that's pretty much all there is to this thing. During gameplay, these systems seem to reset randomly. It could be the timer dipswitch settings that need adjusting, or perhaps my system isn't grounded properly. Anyway, the WideBoy is the better system, since the GB's palette can be adjusted.
The last thing I have to add is that I've dumped the Demo Vision ROMs.
The EPROM data are identical to the "Demo Boy" dumped by Mark Knibbs, so the only real difference is that this dump has the mapper set correctly, and thus has correct colours and graphics when run on an emulator.
Here are some images that most
people probably have never seen digitally captured before: Tetris' Vs. mode,
and a few cheat cartridges' screens.
I captured them directly from the WideBoy's CHR-RAM by making a transfer program running on the Famicom. It probably won't be useful for much more, but hey, it was kinda fun to achieve.